Telephone-exchange system



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TELEPMoNE EXCHANGE SvsEM.

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E. W. HANCOCK. TELEPHONE EXCHANGE SYSTEM.

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Dec. 26, 1922. 1,439,735 E. W. HANCOCK. I

v TELEPHoNE Excl-ANGE SYSTEM.

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E. Vl. HANCOCK. TELEPHONE ExcHANGr-z SYSTEM.

FILED OcT. 20. 1920. I6 SHEETS-SHEET I3 Dec. 26', H922. 1,439,735

E. W.' HANCOCK.

TELEPHONE EXCHANGE SYSTEM.

FILED ocr. 2D. 1920. 16 SHEETS-SHEET 15 E. YJ'. HANCGCK. TELEPMeNe Excmgea SYSTEM.

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@pM/4773A' Patented Dec. 26, i922.

'EDMUND WATT HANCOCK, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION 0F NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Application led October 20, 1920. Serial No. 418,191.

T0 all whom t may con-cera:

Be it known that I, EDMUND lVA'r'r HAN- ooCK,-a citizen of the United States, residing at New York, in the county of New York, Sta-te of New York, have invented certain new and useful Improvements in Telephone- Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone systems and particularly to systems in which machine switching mechanism is usedfor establishing connections between subscribers lines. i

In telephone exchange' systems where a comparatively large number of offices are located in the same area, and the interoffice traffic is hea.vy,.it is found convenient. and economical to dispose of a portion of' this trafiic by routing calls to a central switchingor tandem ofiice, from whence they are then directed to any of the desired outlying offices. Connections are first extended by automatic switches under the control of a register sender, positioned either by subscribers dials or operators equipment, from the originating office over trunks leading to the tandem office. At the tandem office selective switches are operated, in accordance with that portion of the desired designation that identifies the outlying office containingthe called line,.to furtherextend the connection to the.

latter office. Here, dependent upon the typeof the called office, the connection 1s completed automatically to the called line in accordance with the registered designation or is extended to an o-perator, who is advised of the identity'oftheciyangediline by indicating mechanism automatically operated over the extended connection.

Due to the fact that the service requirements of many of the ofiices of the entire exchange system are peculiar to each ofthe particular oflices and differ from those of the others, the equipment, designed for controlling the switches to establish local .connections in a given office, is not suited to cooperate directly in the controlof switches in distant offices for effecting interofce connections. In other words, the register sender in a given office` upon which the called designations are registered, is adapted to control the switches for completing any type of a local call that is required, but on interoffice calls, the sender in the origi. ."-ing ofiice is unsuit-ed in some instances n, "trol dithese offices are designed to receive several classes of calls, it becomes necessary to provide at the tandem office, a register sender capable of recording a large number of class and Oflice designations to enable the extension of all calls routed through the tandem office. To accomplish this, ay controlling equipment is provided at the tandem office, including selective switches which are arranged to be selectively operated 'in accordance with the setting of registers, which registers are positioned by impulses representing the designation of called offices. These switches when positioned, causes the register sender to record the 'office designation to determine the selective extension of the connection to the outlying called office.

Furthermore, since, as above explained, the senders located in originating offices are unable to control all the switching. mechanism involved in an interoffice call routed through the tandem point, it is necessary to transfer the designation first registered on the sender at the originating office to the register sender in the tandem office. lVith the registration tlms transferred, the tandem office sender takes up a corresponding setting and controls the selective switches to extend the calling line to 'a distant called office where it is further extended to the wanted linetherein.

An object of the invention is 'a system in which the designation of a line is recorded on a controlling mechanism, and then transferred to asecond controlling mechanism which controls automatic switches of the panel type to establish a talking connection.

This invention has as another of its objects, the provision in a system of the above character, of a controlling mechanism wherein registers, which are positioned by impulses representing a desired designation, determine the variable operation of a selective switch, which in turn causes a corresponding registration to be produced on the register sender to control the selective ex-` tension of a connection in accordance with the desired designation.

Another object of the invention is the provision of means whereby the registration of a designation on the sender in one oiiice is auton'iatically transferred to a, second office to determine the variable operation of a switch, which switch in its operated position causes the transferred registration to be reproduced on the register sender at the second otice.

A feature of the invention relates'to the provision of a plurality of registers, which take up positions in accordance with designation impulses, and jointly determine the sett-ing of a variably operable switch to cause the registration of the designation on a switch controlling register sender.

A further feature relates to means whereby the settings of the impulse positioned registers serve to select one of a plurality of switches and jointly determine the operation of the selected switch to cause the registration on the sender of .a designation represented by the impulses which posivtion said registers.

A still further feature of the invention relates to the provision of means for transferring the registration on a sender to a set of registers which then determine the operation, of a selective switch to reproduce the transferred registration on the switch controlling registers of a second sender.

These and such other features as-may be contemplated by the present invention will become more clearly understood from a consideration of the following description.

In the drawings, Figs. 1 to 16, when arranged in the order shown in Fig. 17, illustrate the circuits and apparatus of a telephone eXchange system for handling interofiice trafiic in accordance with the principles of this invention.

y |Fig. 1 shows a calling subscribers line terminating in a jack at an operators position in the originating office, and also the circuits of a district selector switch.

F ig.' 2 shows a sequence switch by means of which the operatorstelephoneset is automatically connected to and disconnected from the talking circuit in Fig. 1.

Fig.'3 shows a cord finder switch which operates automatically to associate an allotted register sender with the particular cord circuit that the operator has chosen for use. This ligure also illustrates an auxiliary switch for allotting an idle cord finder and register sender for use.

Fig.\1 illustrates the oiiice keys on the operators keyboard which determine the position of the corresponding'registers in acc'dance with the designation of the called o ce.

Fig. 5 shows the remaining or numerical keys on the operators keyboard and the numerical and stations registers which-take up settings under the control of said keys to record the numerical designation of the called line in the desired office.

Fig. 6 illustrates a set of counting relays and a sender sequence switch for controlling the select-ive movements of the automatic switches in accordance with the designation registered on the ofiice and numerical registers.

In Fig. 7 is shown' the incoming end of a trunk at a tandem oiice terminating in a district selector switch. In this figure, there is also shown an auxiliary switch individual to the district selector for associating therewith an idle register sender in the tandem office.

Fig. 8 shows an office selector switch in the tandem office, which has access to trunk lines leading to outlying oiices.

Fig. 9 shows the incoming end of a trunk from the tandem office terminating in a first or incoming selector switchvlocated in the distant office. Y

Fig. 10 illustrates'a final `selector switch in the distant ofiice, byv means of which, connections are completed to the called subscribers lines.

Fig. 11 illustrates a plurality of intermediate registers and the controlling circuits therefor, to which the office and numerical designations of a called line are transferred from the register sender in a distant calling office.

Fig. 12 shows two selective switches, known as the translator switches, which are variably operable under the control of certain of the registers shown in Fig. 11. There is also shown, diagrammatically, a machine for generating current impulses.

Fig. 13 illustrates a plurality of relay registers adapted to be positioned by impulses sent from the impulse machine as determined by the setting taken by`one of the translator switches.

Fig. 14 shows a class sequence switch and its associated circuits for making the necessary modiications in the operation of the sender to take care of the different classes of calls required.'

Fig. 15 illustrates the counting relay set and sequence switch of thetandem oflice sender for controlling the selector switches in the tandem office andalso the selective mechanism inthe distant called oiiice.

Fig. 16 lshows a sequenceswitch and its .associated circuits which controls the operations involved in the transfer of the registration to the tandem office sender and which also cooperates with said sender in the extension of the connection to the called line. l

The selective switches in Figs. 1, 7, 8, 9

and 10 are of the power driven panel ty e shown lin the patent to Craft and Reynol s, No. 1,123,696, issued January 5', 1915. These switches are provided with five sets of brushes, multipled together and mounted on a common brush shaft. Each set of brushes has access to a sec-tion of the terminal bank containing one-hundred sets of terminals and is arranged to be tripped in the first selecting movement of the switch so as to' make contact with-said terminals.

The cord finder 350 in Fig. 3, is also a power driven switch of the same general structure except that only one set of brushes is provided'and consequently no initial trippingoperation is required. The translator switches 1250 and 1260 in Fig. 12 are likei. wise of the power driven type and differ from the switch shown in Fig. 1, only in the details of operation and in the manner of connecting the brushes and terminals.

The sequence' switches illustrated by the usual convention throughout the several igures of the drawing are of the same construction as the one described in the patent to Reynolds and Baldwin, No. i 1,217,808, issued February 9, 1915.` lVhere but one se- -quence switch magnet occurs in a figure of the drawing, all contacts appearing in the same figure are controlled by such magnet. In Fig. 3, the vallotter sequence switch magnet 310 controls only the contacts located within the broken rectangle at the righthand side ofthe' sheet; whereas the remaining contacts are controlled by the sequence switch magnet 300. In Figs. 4 and 5, the contacts located within the spaces bounded by the verticalbroken lines are controlled by theI magnets correspondingly situated. In Fig. 7, the contacts located within the small dotted rectangle are governed by the sender selector sequence switch 710 and the remaining contacts in this figure are con-v trolled by sequence switch magnet 700'. ln Fig. 11, magnets 1110, 1120, 1130, 1140, 1150, 1160, 1170 and 1180` are located within the spaces bounded by the vertical broken lines and govern the sequence switch contacts appearing in the corresponding spaces. Magnet 1100 in addition to governing the sequence switch contacts to the left of' the left-hand broken line in Fig. 11, also controls all sequence switch contacts appearing in Fig. 12. Y

General descrip tio/n.

According to the system disclosed herein, interofiice calls originating in certain offices of the exchange, such as the one illustrated in Figs. 1 to 6 inclusive. are first routed to a central switching or tandem office, as shown in Figs. 7 and 8 and Figs. 11 to 16 inclusive. Here` the district and office switches are operated in' accordance with the office `designation of the desired line Vto further extend the connection over an outgoing trunk leading to the distant called oflice. If ythe terminating ofiice is arranged for full mechanical connections, such as the office illustrated in Figs. 9 and 10, the incoming and final selector switches are set up in accordance with the numerical designation of the wanted line to complete the establishment of the connection. By placing the interoffice trafiic, or, at least a portion thereof, on the tandem switching basis, it becomes obvious that the switches of' thetandem office must be capable of selecting trunks leading-to any outlying ofiice in the exchange. The register sender. in addition to controlling the district and office switches for making a large number of different office selections, must also be vdesigned to differentiate between the various classes of calls. For example, some of the outlying ofiices to which the connections are extended through the tandem point may be equipped with the selector switches for completing calls on the full mechanical basis, while other ofiices may be equipped with call indicators which are controlled by the register sender in the tandem office to indicate to the operator the numerical and stations designation of the called line. Another class of calls may require the further extension of a connection 95 from the tandem office to a second tandem office from whence it is extended to the terminating ofiice. To meet these operating conditions, the register sender in the tandem office must ,be designed for a large number 100 of class and ofiice settings.

The register sender in the originating office is of the sequence-switch type, arranged to control the sequence switchesby means of reverting impulses. This sender 105 may also control the completion of connections to certain call indicator offices` provided the call indicators are arranged vto workon the reverting` impulse principle.

In such a case it would not be necessary to 110 rout the callthrough the tandem office. In case, however. the call in the originating ofi-ice is one for an oHice equipped with call indicators operating on the code impulse principle, or provided with any other mech- 115 anism which the sender in the originating office is unsuited to cooperate with, it then becomes necessary, as explained; for the connection to be extended through the tandem ofiice. Forthe sake of clearness, the tan- 1'20 dem office sender in the present disclosure. has been` simplified by removing the circuits and apparatus which cause the'transmission of code impulses to position the call indicator in the distant ofiice` inasmuch as the de- .125

scription vto be given herein will/ take acswitch 7 50 at the tandem settings must also be arranged to assume these settings in response to means controlled from the distant calling oiiice.

The originating office in the present instance, is shown to be of the semi-automatic type, with the subscribers lines appearing in jacks at the operators positions. So far as the invention is concerned, however, such oiiice might equally aswell be equipped with full automatic switching equipment. At the initiation of a call, the operator inserts the plug of an idle cord circuit in the jack ot' the calling line and receives from the calling subscriber, the name ot' the called otlice and the number of the wanted line therein. The insertion of the plug Tot the' operators cord circuit in the jack of the calling line initiates the autolnatic operation of an allotted cord iinder 350, which finds the cord taken for use, and associates therewith an idle register sender.

The operators keyboard is equipped with three rows of oice keys, as seen in Fig. 4. By assigning three-digit numbers for the identification of the called oitice, these-three rows of keys, when taken in their several possible combinations, permit the registration of a large number ot office codes. Having received the wanted designation, the operator presses a key in each oty the three rows of office keys, which cause the setting of the three corresponding registers 400, 410, and 420, to register the desired oice designation. She also depresses a key in each of the rows of numerical keys, shown in Fig. 5, to record the number of thc` wanted line.

The district switch 150 is now operated in accordance with the settings of the office registers 400, 410, and 420 to select a trunk 155, 156, which terminates in the district point. The seizure of the trunk 155, 156 causes the operation of the sender selector sequence switch 710 for the purpose of associating an idle register sender with the district selector switch 7 50. As soon as an idle register'sender has been found and associated with the distri'ct selector, the oiice registration recorded on each of the three registers 400, 410, and

4420` is transferred over the trunk 155, 156

Following mechanism to further extend and complete the desired connection.

The tandem office sender disclosed inthe present system has a capacity for the selection of 400 different outlying otiices. For adjusting the relay registers and sender to any one of the 400 different combinations two translator switches 1250 and 1260 are provided Each translator switch is equipped with five sets ot' brushes, only one of the same being shown in the drawings. Each brushset has access toi ai section of the terminal bank containing forty sets of terminals. Each section of forty terminals is divided -into two groups of twenty each, while each group of twenty is further subdivided into groups of ten sets each. The brushes of each translator are multipled together; and also multipled to the brushes of the other translator switch, as illustrated in the drawing. As will be more clearly brought out in the detailed description following, the three registers 1100, 1110, and 1120 jointly determine the selection oil one of the translator switches, the tripping of the proper set of brushes, the selection ot the necessary groups ot' twenty and ten and the selection of the required set of terminals therein.

The impulse machine, diagrammatically illustrated at 1270, consists in practice of a cylindrical drum containing circular rows of metallic segments variously arranged about thecircumference of the drum. Each row may comprise from one to four segments and is so arranged with respect to otherrows as to give a large total number of variations. The metallic segments are spaced apart but are electrically connected together and to a source of battery. In the drawing, where the development of the cylindrical drum is given, battery current is shown to be supplied over the brush 1244 to the continuous metallic segment 1249,

which is understood to be electrically con-- nected to .all metallic segments on the drum. A brushsuch as 1238, 1239, etc., is arranged to engage the metallic segments of each circular row` in the rotation of the impulse machine.

The sets .of the terminals in the banks of the translator switches are wired to the brushes of the impulse machine. shown, each set of terminals in the translator bank'consists of tive terminals, it is possible to obtain a given combination for every set of terminals ofthe entire 400 vsets by wiring` each of these sets to a diii'erent groupof tive brushes at the impulse machine. When, therefore, one of the two translator switches has been selected and positioned von a set of terminals corresponding to the joint settings of the intermediate registers 1100, 1110, and 1120, a code of mpulses is transmitted from the impulse ma- Since, as 

